The liquid crystal display requires proper a driving circuit. The driving circuit generally comprises a data driving circuit and a scan driving circuit. The scan driving circuit utilizes shift registers as the core circuit element in generally.
Ordinarily, the shift register comprises a plurality of shift register units connected in series. The output signal of the shift register unit of the former stage is employed as the input signal of the shift register unit of the latter stage. However, the structures of the most present single shift register units are complex. The occupied area of the shift register is larger after the plurality of the shift register units is connected in series. It is disadvantaged to the narrow frame or non frame design of the liquid crystal display panel. The complex structure can easily decrease the manufacture yield of the liquid crystal display panel.